The Oil Sands Story: Extraction

Dr. Karl Clark, a scientist working for the Alberta Research Council, developed and patented the hot water extraction technique. Building on earlier experimentation by Sidney Ells and others which used hot water to separate oil from oil sands, Dr. Clark's work brought the process to a commercial scale. Oil sand is mixed with hot water creating a slurry. Early methods used large tumbler drums to condition the slurry. Today, hydrotransport pipelines are used to condition and transport the oil sand from the mine to the extraction plant. The slurry is fed into a separation vessel where it separates into three layers - sand, water and bitumen. The bitumen is then skimmed off the top to be cleaned and processed further. Secondary recoveries are made with the middlings zone of the separation vessels to return the smaller quantities of bitumen that would otherwise flow to the settling ponds. Ph levels and temperature are key variables in the process.